Optical Comparators

Danger : Disconnect all power to optical comparator and accessories before starting to work.

This repair should be done by a qualified service person. Please read through all instructions before beginning work.

Before removing the optical comparator fan note the direction of the airflow or if the fan is not working. Look on the fan for an arrow either stamped in the metal or a label indicating the direction of flow. During this replacement you will need to orient the new fan so the airflow is in the same direction. Disconnect the three wires going to the profile fan (there should be three round connectors about 6” from the fan, the wires can be separated at this point). Remove the screws holding the old profile fan in place and mount the new fan in place with the airflow in the correct direction. The new optical comparator fan has 5-millimeter threads for mounting or 4-millimeter screws can pass through the threads. Depending on the mounting style used for your optical comparator. Connect the two power wires and green ground wire of the new fan (it does not make a difference which of the black fan wires goes to which of the black and white supply wires). After the fan installation is complete reconnect the power to the optical comparator and accessories. The new fan should run when the machine power switch is turned on.

Optical comparators are designed and manufactured so far as is reasonably practical to allow its safe operation when used in accordance with the safety instructions. Optical comparator must be used in position that does not constitute a hazard, where the operator and maintenance staff have free access to the control and maintenance of the equipment, and are not subject to any external hazards. Services should be conducted by an authorized person, to approved safety standards. The electrical supply should be taken from a correctly rated source.

Power requirements

The standard optical comparator is usually supplied to accept 110-120V AC, 50-60 Hz main power. It may also be configured to accept either 220-240V AC, 50-60HZ or 100V AC, 50-60Hz. Unless clearly labeled (next to the power input plug) optical comparators are configured for 110-120V AC, 50-60Hz. Listed below are wire color codes:

Note optical comparators must be plugged into an outlet rated at a minimum of 15A and must not be operated without an adequate ground connection.

Optical comparators are designed to work in a normal workshop environment but it is important to locate the unit as far as possible from sources of grinding grit, oil mist, and vibrations. Where possible the projector should be located with the screen facing away from direct sunlight and overhead lighting.

Bench-top optical comparators should be placed on a strong sturdy bench capable of securely supporting a minimum of 550lbs/250Kg with a point pressure capability minimum of 165psi. Dorsey Metrology optionally supplies a cabinet/stand designed for this application. Canopy and curtains are not provided as standard, but are available as an optional extra fitted at the factory on the projector stand. These items are strongly recommended when using lenses of high magnification or with surface projection of difficult components.